Embryonic appearance of alpha, beta, and gamma crystallins in the periodic albinism (ap) mutant of Xenopus laevis

Abstract

The appearance of the crystallins during lens development in the periodic albinism (ap/ap) mutant of Xenopus laevis has been studied. Using antibodies specific for total crystallins, alpha + beta crystallins, and gamma crystallins in the immunofluorescence technique, the first positive reaction for all could be demonstrated in the Nieuwkoop-Faber Stage 31 lens rudiment. The antibody to alpha + beta crystallins exhibited differences in intensity from cell to cell in the early rudiment, while the reaction to the other antibodies was uniform throughout the rudiment. As lens differentiation progressed, immunofluorescence was restricted in all cases to the lens fiber area, up to and including Nieuwkas positive, however, for total lens crystallins. These results are at variance with earlier studies on lens development and the crystallins in wildtype (+/+) X. laevis, where a positive reaction for gamma and total crystallins could be detector total lens crystallins. That this divergence in the mutant is due to a pleiotropic effect or directly to the inductive failure of the endomesoderm to initiate melanogenesis, is discussed.